Wow, this gives further insight into the Marylike-Standards of modesty.
It appears some of the bare minimum standards (skirts just past the knees) were for girls, but not appropriate for grown women. Based on Pope Pius XI's standards below for receiving audiences with women, Cardinal Maffi wrote a pastoral letter forbidding women who were not in ankle-length skirts from receiving Holy Communion and Confession. Sleeves above the elbow were also forbidden, for both girls and women.
From The Catholic World in Pictures, 28 September 1925:

I wonder if anything like this exists for men on modesty or even things like jewelry etc necklaces, bracelets, earrings, non-wedding rings which are all common nowdays.